Abstract : A study is made of the hypersonic flow over a slender wedge which is oscillating in pitch with amplitudes of the order of wedge semiangle. The hypersonic small disturbance equations are solved for small values of the reduced frequency parameter. The solution is presented in the form of a series expansion in that parameter, the zero term describing the quasi-steady flow and the first perturbation terms representing the unsteady departures from it. In the presentation of the results some attention is paid to an 'equivalent phase shift' that is defined as the angular distance between the amplitude peaks of the quasi-steady and the complete solution. This phase shift has been found to be relatively independent of the amplitude of oscillation and also of the hypersonic similarity parameter. Numerical coefficients are tabulated which can be used for a rapid calculation of local flow quantities at the surface and in the flowfield around the wedge for a wide range of the hypersonic similarity parameter and for two values of the adiabatic exponent. (Author)